The Finished Gem; Colombian Emerald Part III

By Richard W. Wise, G.G.

©2007

We spent most of the afternoon watching and asking questions about various aspects of the cutting process. It was a unique opportunity to sit at the feet of a master, to watch, listen and learn. (image: left: Murmurs of a goddess; Blue Morpho Butterfly of Colombia)

Step #2: Dopping

Before the faceting operation can begin, the pre-formed stone is first affixed to a stick to allow the lapidary to handle it. This age old method involves embedding the preform in a dab of shellac at the end of a 1” wooden dowel. The shellac is first heated until sticky over the flame of an alcohol lamp. The stone is placed at just the right angle and pressed into the shellac and allowed to cool. This process is repeated several times during faceting.

Step #3: Placing the Facets

Faceting is the most precise phase of the cutting operation. Facets must be cut uniformly in a precise pattern to bring out the brilliance of the gem. The faceter can only do what the pre-former has determined. If the ratio between the width and depth is correct the stone has the potential to be fully brilliant, if it is cut to shallow and there is insufficient depth, light will leak out the pavilion creating what is called a window in the gem.

Argotty’s Well:

Adolpho Argotty likes a window; I’ll go further he seems to actually prefer a windowed stone though his definition of a window is not quite what you might expect. He is not using the word to describe a stone through which you can read the New York Times by placing the paper beneath the table of the gem. He likes to push the envelope, to setup the proportions in such a way that the viewer can look into the table of the finished gem and see right down into the heart of the stone to the depth of the pavilion facets. The area under the table does not refract light, rather it draws the eye in and deep into the very heart of the gem. This requires a subtle touch. Viewed perpendicular to the table, an emerald fashioned in this way does not have a true window, but the center of the stone is like a deep well of green with little or no refracted light visible through it. This sort of window, he believes, allows you to see the color and appreciate the crystal of a fine emerald.

Step #4: Polishing:

Polishing is the final, actually the final series of steps in the cutting process. It is like the wedding night, the time when the virginal and reluctant bride fully reveals her charms. The final polish allows you to evaluate the four Cs of the connoisseur, (Color, Cut, Clarity and Crystal) The cutting/polishing process uses a series diamond compounds that like sandpaper are divided into various sizes or grits. Grits may be divided into two basic types; cutting grits and polishing grits. The pre-former begins with a fairly coarse, 300 grit, that allows him to shape the stone. The polisher uses several progressively smaller grits ending with 15,000 diamond grit to secure the final mirror-like surface luster.

The Legend of Fura Tena:

As with many legends there appears to be more than one version of this one. According to one version, a short one, in the beginning there were two Gods; a male named Fura and his consort the goddess Tena. (follow this link to a very different version) It seems that Tena had a roving eye and she took up with another god named Zarue and they became lovers. When Fura discovered that his lover had been unfaithful he cried and his tears dried into emeralds. Tena's murmurs of sadness became the beautiful blue butterflies of Colombia (Morpho didius Hopffer). The creator turned them both into stone and turned Zarue into a river (the Minero) that runs eternally between them.

This formation (right) shot from above is known as FuraTena. On the valley side and not visible here the monolith is divided into two cliff faces and separated by the Minero River. (photo: Richard W. Wise) A better view by Robert Weldon can be found here

Not quite a goddess but the lovely young lady pictured at left, an occasional emerald broker, has no doubt broken the odd heart and caused the shedding of more than one tear.

Next: Buying Emerald; A Journey to a rural miner's market in Boyaca...Stay Tuned

Learn the truth about how Emeralds and other fine gems are graded and priced!

Follow me on gem buying adventures in the pearl farms of Tahiti. Visit the gem fields of Australia and Brazil. 120 carefully selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world's most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur's Guide To Precious Gemstones.

“Wise is a renowned author... He’s
done a marvelous job of this first book, monumental work, a tour de force...My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

whether you like to know what the best colour is in Tanzanite, or how to grade a Diamond, you will find it in this book. No other book I read before dealt with this topic is such detail as Richard Wise's masterpiece."

A. Van Acker, FGA
Amazon June 2005

"Secrets Of The Gem Trade: The Connoisseurs Guide To Precious Gemstones by Richard W. Wise is an impressive new reference for dedicated dealers and collectors of gems, gemstones, and ... pearls. Introducing and descriptively exploring each and every gem covered in the easy-to-use reference, Secrets Of The Gem Trade contains an illustrated summary of each stone inclusive of its history and general information, hue and tone, saturation, which may be noticed as the finest, an understanding of the particular gems rarity, and the caution for synthetics and how to depict them, however depending upon the stone there may be description of clarity, color fading, multi-color effect, etc. Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference."

Midwest Book Review
April 2006

Only $31.95. Read a couple of chapters online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com

Rough Roulette; Colombian Emerald Part II

By Richard W. Wise, G.G.

©2007

"Round and round she goes and where she stops, nobody knows."

I have heard it said that each time you put an emerald on the wheel the chances of breaking the stone are about 50/50. I recall one hot and dusty afternoon in the late 1980s I was sitting with some friends at a cafe in Teofilo Otoni, a town which was, at that time, the gemstone capital of Brazil. A ragged looking garempiero rode by on a motorbike, turned around and rode back to the cafe. He knew my friend, a Brazilian cutter, so he pulled a dirty scap of cloth from his shirt pocket and let us have a look. The cloth contained an emerald crystal from the mines ant Santa Terezinha de Goiás. The miner had rode all through the night to bring his find to Teofilo. During the 80s Goiás produced emerald that rivaled some of the better gems Colombia had to offer. (pictured left: Entrance to the shaft at La Pita Emerald Mine. Guacharos wait for the tailings. Photo Richard W. Wise)

The perfectly formed hexagonal crystal showed a verdant medium-dark green color that looked exceptionally fine. I don't recall the actual weight (somewhere in the 25 carat range) but the crystal was about the size of my index finger. This crystal lacked the jewel-like transparency of the Colombian crystals pictured in Part I and was difficult to evaluate. I could see the pepper like inclusions typical of of Goiás emerald but little else.

The asking price of the Brazilian crystal was a quarter of a million dollars. Long story short, I didn't make an offer. I thought the crystal lacked the transparency necessary to evaluate it and I wasn't prepared for a quarter of a million dollar spin of the wheel. I later heard that the crystal had been sold for something close to the asking price and that when it was put on the wheel it had literally exploded leaving the buyer with nothing to show for his purchase.

High Rollers:

Hurry, hurry, hurry and welcome to the high stakes world of the rough buyer where every parcel is a gambol. In this world, where a single bet may exceed a million dollars, the dealer across the table from me is a high roller. The parcel so casually scattered across the desk in front of me is a big time rise. Perhaps 1400 carats, it is from the new mine, La Pita, a complex of adjacent shafts in the Colombian state of Boyaca. One mine actually bears the name La Pita, the others are Consorcio, Cunas, Totumos and Polveros. In a country where the old mines have been producing since before the Conquistadors conquered their local owners in the mid Sixteenth Century, serious commercial mining only began at La Pita in 1997. (Pictured left: the author works his way through a half mile tunnel to the surface. Foreground, miner pushes cart full of mine tailings, these will be given to guacheros waiting at mine entrance for further sorting: Photo: Ron Ringsrud)

We are about to watch the fashioning of two of these crystals into gemstones. In this high stakes world a dealer needs an edge. Having a lapidary with the skill of Adolpho Argotty is just such an edge. According to Argotty, in his workshop, loss on the cutting wheel is perhaps 4% and that is perhaps why Argotty is rated the best. He is presently traiing the second generaltion, his niece, Fernanda, who sits at a wheel at his side (see image above right).

Argotty doesn’t just pre-form the stone he supervises the entire process:

“Would you ask an architect to just put up the bones of a structure and let others finish it?” he asks.

(images: above: Adolpho Argotty, holds forth: Picture Richard W. Wise) It takes just about a half an hour. Argotty works away the emerald held between his thumb and forefinger. He grinds a bit then holds the stone up and squints at it in the sunlight all the time carrying on an animated conversation in Spanish with my partner Ron Ringsrud. Ron loves Colombia. He deals exclusively in Colombian Emeralds, has been coming to Bogotá for twenty-five years and speaks fluent Spanish.

The workshop is surrounded by windows on three sides. The light is good. The two crystals have been blocked out, that is to say, they are now the size and shape of the finished gem. Argotty decided to cut the best crystal into a standard rectangular emerald cut. The stone started out at 7.17 carats it now weighs 4.77 carats and it is ready for the faceting wheel. Argotty is excited about this gem. He hands it to Maria Fernanda to polish the table, he wants a closer look.

She hands it back.

"This one", he says, "will be worth at least $10,000 per carat."

The second stone which began at 8.53 carats has been shaped into what Argotty is calling a rose cut. I am confused because the stone obviously has a pavilion and looks very much like an antique style emerald cut with overly large corners. Later we figure out the problem is in translation, Argotty means an old style cut which this stone obviously is. Even before polishing commences we see visible inclusions in the stone. It now weighs 6.44 carats.

Step #1 Sealing & Certification:

In Adolpho Argotty's workshop, preformed stones are dipped into hot paraffin. The objective is to seal any surface breaking fissures to insure that no residue of the polishing compound makes its way inside the stone.

Colombian cutters become a bit testy when the subject of lab grading is raised. If you love emerald you must be prepared to accept some surface breaking fissures and yes, cedar oil is universally used as a treatment to hide these fissures. However, both dealers and cutters feel that they are getting a bad rap from some American and European Gem Labs. Most labs use a uniform four step grading process to grade the level of enhancement: none, minor, moderate and heavy. Gubelin adds insignificant between none and minor and AGL (American Gemological Laboratories) uses its own proprietary scale. Columbian Esmeraldaros believe that this system lacks consistency. The labs, they contend, are afraid to use the term none. According to Argotty, he has delivered emeralds that he personally cut and knows to be totally without enhancement, to major European labs which in turned issued reports claiming these emerald contained a filler. The reader should bear in mind that a certificate grade of none is in no sense a clarity grade,the stone can still look like a broken coke bottle. It just contains no filler, no clarity enhancement.

I examined hundreds of finer stones in the course of my week in the Bogata market and with but a single exception, every stone I saw had some surface breaking fissures. Taking Ron Ringsrud's advise I rejected any stone with fissures on the crown or girdle or those with fissures on the pavilion that I felt might n anyway compromised the durability of the stone. This, by the way, would make a good definition of the term minor enhancement.

Next, Dopping, Faceting and Polishing. Stay Tuned.

Learn the truth about how Emeralds and other fine gems are graded and priced!

Follow me on gem buying adventures in the pearl farms of Tahiti. Visit the gem fields of Australia and Brazil. 120 carefully selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world's most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur's Guide To Precious Gemstones.

“Wise is a renowned author... He’s
done a marvelous job of this first book, monumental work, a tour de force...My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

whether you like to know what the best colour is in Tanzanite, or how to grade a Diamond, you will find it in this book. No other book I read before dealt with this topic is such detail as Richard Wise's masterpiece."

A. Van Acker, FGA
Amazon June 2005

"Secrets Of The Gem Trade: The Connoisseurs Guide To Precious Gemstones by Richard W. Wise is an impressive new reference for dedicated dealers and collectors of gems, gemstones, and ... pearls. Introducing and descriptively exploring each and every gem covered in the easy-to-use reference, Secrets Of The Gem Trade contains an illustrated summary of each stone inclusive of its history and general information, hue and tone, saturation, which may be noticed as the finest, an understanding of the particular gems rarity, and the caution for synthetics and how to depict them, however depending upon the stone there may be description of clarity, color fading, multi-color effect, etc. Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference."

Midwest Book Review
April 2006

Only $31.95. Read a couple of chapters online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com